Evaluating the role of insect pollinators in the viability of true seeds of shallot in tropical agroecosystems

Abstract

Pollen transfer in tropical agroecosystems to increase seed production has received limited research, notably on shallot pollination and insect pollinators. This study evaluated how insect pollinators optimize shallot seed production in tropical agroecosystems, i.e. Batu and Malang Districts in Indonesia. This study was conducted from June to October in 2023. We examined pollinator diversity, foraging behavior, and the effectiveness of dominating insect pollinators during umbel flower anthesis, as well as visiting insect foraging and visiting patterns. We assessed pollinator effectiveness by comparing visitation rates under four treatments. A total of 21 insect species belonging to three orders visited the shallot flowers, of which 14 species have the potential to act as pollinators. Apis cerana Fabricius, 1793 (Hymenoptera: Apidae) and Lucilia sericata (Meigen, 1826) (Diptera: Calliphoridae) emerged as potentially effective pollinators. Air temperature significantly influenced pollinator activity in visiting anthesis umbels. Evaluations of pollinator efficiency showed that A. cerana was more efficient than L. sericata in promoting the production of true shallot seed and has a significant role in ensuring high-quality pollination. This highlights the necessity of comprehending the specialized contributions of pollinators for shallot seed production.